Apple's OS X Lion released today, and for the first time, the only way to grab a copy is through the Mac App Store. While this convenience might encourage you to upgrade immediately (for the price of $29), we've got a short checklist of things you need to do before installing Lion.

1. Check system requirements.Is your system even compatible with Lion? Go to the Apple menu > About the Mac to find out. You'll need:

Intel Core 2 Duo, Core i3, or Core i5, Core i7, or Xeon Processor

2GB of RAM (aka "Memory")

Mac OS X 10.6.6 or later (Snow Leopard), including the Mac App Store

At least 4GB of storage for Lion

2. Install software updates. Go to the Apple menu > Software Update, and download and install all the recommended software.

3. Back up your Mac. Before installing Lion, back up your system, as a new operating system can sometimes result in corruption. We recommend using Time Machine, but you can find step-by-step instructions for other options here.

4. Do a little app maintenance. As MacFixit's Topher Kessler suggests, uninstall any apps and add-ons you don't use (including apps that run in the background and apps that tweak your operating system). Then head to Roaring Apps and check to see if the applications you keep are compatible with Lion.

Once you've checked these five things off, you're ready to install Lion through the Mac App Store.

Note: You can install one purchase of Lion on multiple machines, as long as they're authorized to the same Apple ID used at purchase. In the App Store, go to the "Store" menu, and sign in with the appropriate account.